Integrated circuit packages are made in a variety of electronic configurations. These packages, however, are commonly configured within standard packages: one of these is often referred to as dual in-line packages, hereafter referred to as DIPS. These DIPS are used ina wide range of electronic applications, frequently including military apparatus. Because of the substantial reliability requirements of such DIPS, a variety of tests have been developed to assure proper functioning of these DIPS. These tests, including, for example, a burn in test required as a military prescreen, often involves the insertion of the chips into an "electrical circuit" for repetitive or other types of testing. In view of the very large number of DIPS tests, it has been common to develop a test board designed to simultaneously receive a plurality of DIPS for common and efficient testing. These test boards must be designed to receive a plurality of DIPS from automatic insertion machinery. After testing, the DIPS are automatically removed and a new set inserted. Consequently, the sockets designed to receive the DIPS must provide good electrical connections to the DIP leads and further must be designed to readily receive and securely hold the DIPS during the testing cycle. The contact between the socket and the DIP must be such as to permit easy insertion and removal, while nonetheless providing good electrical connections.
A wide-range of test boards are used to receive the many different types of DIPS. Thus, for example, the test boards used for memory DIPS are different from those used for logic DIPS. The circuit on these test boards are generally formed in the lower surface of the test board with some components such as capacitors and resistors secured on the other side of the board adjacent or in between the sockets designed to receive the DIPS. Heretofore, these sockets have ordinarily been secured by solder to a printed circuit board, and the associated electronic components, such as resistors and capacitors, are placed on the test board with their leads appropriately soldered to the test board circuit. Since these components occupy a portion of the test board surface, the remaining space left for sockets to receive the DIPS is limited. In turn, this means fewer DIPS can be tested at a given time.
Since testing and prescreening of DIPS require the use of expensive ovens with limited interior space, it is important to provide a test circuit board with as many sockets designed to receive DIPS as possible. By using smaller resistors, such as ceramic chip resistors, capacitors, or other passive components and by providing a socket particularly designed to receive both DIPS and one or more ceramic chip resistors or the like in lieu of axial resistors, a considerable space savings upon the surface of the printed circuit board may be effected. As a consequence more DIPS may be tested at a given time on a board.
Several attempts have been made to provide DIPS test boards that achieve these results. Insofar as the applicant is aware,the most relevant efforts are exemplified by U.S. Pat. No. 4,478,476 which issued Oct. 23, 1982 to Jones. That patent generally discloses a socket for use on a test board. However, it makes no provisions for the integration within the socket of means for receiving a discrete component such as a capacitor or resistor.
Other references illustrative of the prior art include, for example. U.S. Pat. No. 4,356,532 issued Oct. 26, 1982, U.S. Pat. No. 4,080,026 issued Mar. 21, 1968 and U.S. Pat. No. 4,116,519 issued Sept. 26, 1978.
Accordingly, it is an object of the present invention to provide a socket for securing DIPS to a circuit board including, but not limited to, test circuit baords.
A further object of the present invention is to provide an improved socket for a variety of circuit packages, such as DIPS, pin grid arrays, leadless chip carrier packages, flat packs, and the like that permits a more compact arrangement of the integrated circuit packages on the board.
A further object of the present invention is to provide an improved integrated circuit socket adapted to receive combinations of an integrated circuit package and a variety of discrete components for electrical connection of the components and integrated circuit package to the circuitry of a circuit board.
A futher object of the present invention is to provide a means for achieving greater flexibility in mounting an integrated circuit package on a circuit board by incorporating into the socket a means for receiving discrete components such as resistors and capacitors.
A further object of the present invention is to provide an improved circuit board having a plurality of sockets secured thereto in electrical contact with the circuit of the circuit board, wherein the sockets are adapted to commonly receive both integrated circuit packages and discrete passive components.
A still further object of the present invention is to provide an improved socket for receiving integrated circuit packages in a manner that permits ready insertion and removal of the packages into the socket, thereby permitting use of the sockets on a test board circuit.
Another object of this invention is to provide means for solderless secure components within a socket and in conductive contact with leads of an integrated circuit package.